Development 2 Flashcards
Morphogenesis is the _____ and it occurs during Organogenesis & Gastrulation
Cellular & Tissue based process by which animal bodies take shape.
Define Gastrulation
Inward folding of the Blastula - forms Gastrula
SEQ Gastrulation in Sea Urchins (4 Steps)
- Cells at the Vegetal Poll migrate to the blastocoel
- Vegetal Plate forms - cells flatten, fold inwards
- Archenteron Forms
- Archenteron fuses with blastocoel wall - forms digestive tube.
Name the end results of Gastrulation in Sea Urchins (3 - MCA)
-Mouth
-Cilia
-Anus
SEQ Gastrulation in Birds
- Development
2.) Migration
3.) Production
- Embryo forms 2 layers - Epiblast (forms Embryo) & Hypoblast (forms sac around embryo)
2.) Some Epiblast cells migrate to the mesoderm (midline)
3.) Produce Primitive Streak (Blastopore)
SEQ Gastrulation in Humans
1.) Blastocyst (cells around central cavity), consisting of Trophoblast and Inner Cell Mass forms.
- Inner Cell Mass becomes Embryo
- Forms Epiblast & Hypoblast
2.) Trophoblast (outer layer of cells) secretes enzymes
3.) Enzymes erode area of endometrium (layer in Uterus) during implantation & become support tissue - allow the Embryo to penetrate
4.) Inner Cell Mass (cluster of cells)
During Human Gastrulation, what happens to Epiblast Cells that:
A. Stay in Place at the top
B. Move to Middle
C. Move to the bottom
A. Ectoderm
B. Mesoderm
C. Endoderm
What are 2 Functions of the Extraembryonic Membranes that result in Human Gastrulation
- Contain Fluids
- Form blood vessels
What is Neurulation?
Process of forming the Nervous System
SEQ Gastrulation in Humans: What occurs during implantation?
trophoblast thickens & extends fingerlike projections into the endometrium
What is the trophoblast?
connection between embryo & uterus
What is an Amnion?
Bag of Waters
In Morphogenesis, the notochord ___ the neural plate
Induces - Stimulates neighboring cell (paracrine signaling)
Neural Plate rolls into the ____, which then becomes the ___.
The Aneterior Portion produces the ____, and the remaning portion forms the ____
1.) Nervous Tube
2.) Central Nervous System
3.) Brain
4.) Spinal Cord
During Migration, ____ cells migrate to form nerves, teeth, skull bones, etc
Neural Crest
_____ are blocks of Mesoderm cells lateral to the Notochord. They contribute to repeating structures, such as the RIbcage
What is the difference between identical and fraternal twins?
Identical - Shared Placenta (ISP)
Fraternal - Separate Placenta
SEQ Early Human Development
- IMplanted Embryo secretes Human Chorionic Gynadotropin (hCG) - acts as LH
2.) Progesterone & Estrogen from Corpus Luteum are maintained during the 1st trimester
3.) Nutrients for the Embryo are made/secreted from the Endometrium
3.) Trophoblast mixes with Endometrium - Forms Placenta
5.) Placenta provides nutrients to Embryo
SEQ BIrth
1.) Estradiol from ovaries activate Oxytocin receptors on Uterus
2.) Oxytocin stimulates Labor Contractions - secreting more oxytocin
3.) Oxytocin stimulates Placenta to make more Prostaglandins
4.) More contractions are stimulated
